Carbon stick attachment for motion picture projector lamps



Nov. 7, 1944. T. KUEHL 2,362,281

CARBON STICK ATTACHMENT FOR MOTION PICTURE PROJECTOR LAMPS Filed Sept. 30, 1945 Patented Nov. 7, 1944 UNITED STATES PATENT OFFIGE CARBON s'riok Arracnns rmamohos morons PROJECTOR LAMPS Theodore Kuehl; one, Mich. Application September 30, 1943, Serial No. 504,42 13 3' Claims.

This invention relates to an attachment for arc-type motion picture projector lamps and the primary object of the invention is the provision of means to permit short length carbon sticks or ones whichhave been partly consumed and not of a length to assure the operation of the lamp for the complete showing of the reel of film to beutilized and toautomatically bring into operation another carbon stick when the stub or short length of carbon stick has been approximately all consumed or burnt-out; so that there will be no interrupt-ion of light for the showing of the reel of film and which will provide a large saving in the oost of operation of a projector lamp by permittingthe; use of said carbon sticks heretofore discardedl With these and other objects in view as will become more apparent as the description proceeds, the invention consists of certain novel features of construction, combinatio'nand arrangement of parts as will be hereinafter more fully described and claimed.

For a complete understanding of my invention, reference is to be had to the following description and accompanying drawing in which- Figure l is a side elevation illustrating an attachment constructed in accordance with my invention and showing its application to a positive carbon stick holder to an arc-type motion picture projector machine,

Figure 2 is a view similar to Figure 1 showing the position of the attachment after the stub or short length of carbon stick has been utilized and the bringing of another carbon stick into operative position,

Figure. 3 is a sectional view taken on the line 33 of Figure 1,

Figure 4 is a large fragmentary sectional view showing the construction of the jaw for the support of the stub or short length of carbon,

Figure 5 is a fragmentary view partly in section showing a part of the bracket which supports the arm carrying the stub or short length of carbon stick in operative position until such time that approximately the entire amount of the stub or short length of carbon stick has been consumed.

Referring in detail to the drawing the numeral 5 indicates a negative carbon stick and 6 a positive carbon stick of an arc-type motion picture projector lamp, the positive carbon stick being mounted in the usual type of bracket 1 to advance in the direction of the negative carbon stick as the two sticks burn from each other. It is to be understood that the bracket 1 is advanced and moved by the conventional type of mechanism now found in projector lamps in use, p h

A bracket 8 is mounted in the lamp below the space between the adjacent ends of the carbon sticks 5 and 6 and where the arc takes place. and hasa laterally extending portion 9 and a vertically arranged portion [0 the free end portion of which isbifurcated as shown at I I; The bifurcation H forms a slot in the-portion l0 opening through the free end thereof and which has different widths forming shoulders l2 acting as a seat for an'arm i3 and itsclamp ld. The clamp I4 is for the purpose of detachably securing to the arm l3 carbon sticks of short lengths or ones which have been partly utilized and other lengths that will notassure the operation or illumination of thelampfor the complete showing of a reel of film. The arm,l 3 is pivotally mounted on a bracket I -5 including a collar i6 mounted on a portion of the carbon stick bracket 1. The arm may pivot relative to the bracket 15.

The clamp It includes a relatively fixed jaw I! and a, movable jaw I8. The jaws are pivotally connected as shown at I!) While the jaw I! is fixed on the arm I3. The jaw I! may rest upon the seat l2 of the bracket 8 for supporting the stub or short length of carbon in operative relation with the negative carbon, as shown in Figure 1, and after the carbon stick bracket 1 of the lamp is advanced a distance wherein the stub or short length of carbon stick has-been substantially consumed, the jaw l1 moves beyond the seat I2 bringing the arm [3 for movement in the slot II and bringing the stub or substantially consumed length of carbon stick into an inoperative position as shown in Figure 2 with respect to the negative stick 5 and allowing the positive carbon stick carried by the bracket 1 to engage with the stick 5 and thereby become located properly in respect to the negative carbon stick for the producing of the arc light. The shifting of the position of the arm l3 from that shown in Figure 1 to that shown in Figure 2 will take place very rapidly when the jaw l1 moves off of the seat [2 so that the carbon stick 6 assumes an operative position soon after the movement of the short or consumed stub has moved out of operative position, permitting the operation of the projector lamp to continue without interruption of the are light and c onsequently the showing of the reel of film.

When the stub or short length of carbon stick has been substantially consumed, the positive car- Icon stick 6 has moved into the name and becomes red hot, causing the latter to gas, so that when it takes the operative position, it is conditioned to cooperate with the negative stick 5 in producing the are light.

The jaw 18 has a recess adjacent the pivot l9 and as indicated by the character 20 in which is journaled a cam 2| that rides the jaw IT. The cam 2i may be rotated by a finger piece 22. The cam provides means for forcing the jaw 18 into clamping relation with respect to the jaw I! to firmly hold a stub or short length of carbon stick and provides a convenient means whereby the stub or short length can be freed after practically the full use thereof has been made.

From the foregoing description taken in connection with the drawing, it will be seen that a very simple attachment has been provided, easily adaptable to a carbon type motion picture projector lamp and will provide facilities for the utilizing of a short length of carbon stick heretofore wasted or discarded, consequently bringing about a much cheaper operation of the projector lamp. Further it will be seen that the attachment is substantially automatic in operation, that is in the moving of the short lengh of-carbon sick or stub into inoperative position and another positive carbon stick into operative position when the short length of carbon stick or stub has been substantially consumed.

While I have shown and described a preferred embodiment of my invention it will be understood that minor changes in construction, combination and arrangement of parts can be made without departing from the sprit and scope of the invention as claimed.

Having thus described my invention what I claim is:

1. In combination with a movable electrode holder of a motion picture projector lamp and a carbon stick pivotally supported thereby for movement into operative position from an inoperative position by gravitation, a second holder carrying a second carbon stick and movable relative to and with said first mentioned holder and supporting the first mentioned carbon stick in inoperative position while said second mentioned carbon stick occupies an operative position, and means supporting said second mentioned holder with the second mentioned carbon stick in operative position, and automatically freeing said second mentioned holder for gravitation to bring the second mentioned carbon stick into inoperative position after a given movement of the first mentioned holder.

2. In combination with a movable electrode holder of a motion picture projector lamp and a carbon stick pivotally supported thereby for move ment into operative position from an inoperative position by gravitation, an arm pivoted to said holder, a clamp carried by said arm to receive a short length of carbon stick, and a bracket having a bifurcated end with the bifurcation of different widths to form supporting shoulders, said supporting shoulders supporting the clamp to support the second mentioned carbon stick in operative position with the clamp supporting the first mentioned carbon stick in inoperative position until said clamp is disengaged from the shoulders by a given movement of the holder permitting the second mentioned carbon stick to gravitate into inoperative position and the first mentioned carbon stick to gravitate into operative position.

3. Ina device of the class described, a main carbon holder, a movable support to which the main carbon holder is pivoted, a supplemental carbon holder pivoted to a part of the main carbon holder, and means for supporting the sup plemental carbon holder in active position.

THEODORE KUEHL. 

